1. Field
The present invention relates to a quantum dot sheet, and a light unit and a liquid crystal display including the same.
2. Description of the Related Art
Unlike emissive displays such as plasma display panels (PDPs), field emission displays (FEDs), etc., liquid crystal displays (LCDs) are non-emissive displays that are incapable of emitting light by themselves, and thus incident light from the outside is required to display an image. Thus, a backlight unit (BLU) for emitting light is positioned at a rear side of an LCD.
A cold cathode fluorescent lamp (CCFL) has been utilized as a light source for the BLU for the LCD. However, as sizes of the LCDs become larger, when the CCFL is utilized as the light source, there is a problem that luminance uniformity is not guaranteed and color purity deteriorates.
Recently, a BLU utilizing three color light-emitting diodes (LEDs) has been developed, and the BLU utilizing these three color LEDs as a light source can implement high color purity, thereby being applicable to high quality display devices. However, the LED BLU has a drawback that its cost is very high compared with that of the BLU utilizing the CCFL as the light source. In order to overcome such a drawback, a white LED is being developed in which light emitted out of a single color LED chip is converted into white light.
However, while the white LED is economically feasible, it has a problem that color purity and color reproducibility are low, and thus efforts for utilizing a semiconductor nanocrystal as the BLU have recently been made to improve the color reproducibility and the color purity, and to ensure price competitiveness.
However, such a semiconductor nanocrystal also has a problem in that it emits light in all directions, and thus the light directed in a front direction is no more than about 50% at maximum.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.